The control system of an ebike is usually mounted on the handlebars, in a position which is easy to reach with your hands and with your sight.
The simplest models integrate in a single unit both the controls and the part that gives informations to the cyclist. Sometimes, as in the model in the picture on the left, there is not even a display, but a series of LEDs that indicate the state of charge of the battery, and the selected level of assistance, and the only operation that you can perform is in fact choosing the level of assistance, usually among three possibile options. This regulation has obviously an important effect on the range of the ebike, as the battery will discharge more quickly if you choose a high level of assistance, and viceversa. Being able to choose the level of assistance is useful in those cases in which there are still a few miles to go before you reach your destination, and the battery has little “juice” left: by lowering the level of assistance you can make sure that you will reach your destination without too many problems.
Other models, on a higher price range, are similar to the one in the picture above. Here too everything is integrated into a single unit, positioned on the handlebars not too far from the left hand, so that it is not too difficult to reach with your thumb. In this case however an lcd screen is incorporated, and this allows the user to see some useful data, such as speed and distance travelled; in this model it is also possibile to choose among a wider range of levels of assistance (7), in order to regulate more precisely the power delivered by the motor.
Ebikes on a medium to high price range should have a more evolved system, similar to the one in the picture above: the control buttons are on the left, and they are separated from the display, which is positioned centrally. Such a solution offers an improved user experience: the buttons are very easy to reach with the left thumb, without the need to move the hand from its normal position; at the same time the central display is easy to read, and offers a wide variety of data, such as pedalling cadence, the watts delivered by the motor, an estimate of the available range in miles, and more.
The most recent models, such as the Nyon display from Bosch, sport a color display with gps and Bluetooth technologies, which can connect to the smartphone to offer alerts about incoming calls and messages.
Actually, if you want maximum flexibility, it is probably more useful to make a better use of something that we all have nowadays: a smartphone. For this reason, in many high-tech ebikes often there is no display at all: the ebike is controlled through an app that you have to download on your phone, which can be safely mounted on the handlebar and connected via USB to the ebike, in order to keep it charged (a very useful thing if you want to use the smartphone as a navigator). Once you connect an ebike to a smartphone, the only limit is in the inventiveness of app developers. For instance, some systems also work as an automatic block: once the user (carrying his/her smartphone) walks away from the ebike, breaking the Bluetooth connection, the ebike automatically locks, preventing the theft of the bike.
What is the best system? We believe that the best system is the safest, the one that allows you to control your ebike without moving your hand from the handlebar, and without having to look at the buttons (that means, with buttons that are easy to feel, even with winter gloves on). The system where the buttons are separated from the display are the ones that are the best from this point of view, even though many simpler systems, if well-positioned on the handlebars, can reach the same ease of use. Ebikes that are controlled via a smartphone are less safe, because they lack a tactile feedback: it is therefore always necessary to look at the display (while you should really be looking at the road) even to perform a simple operation such as changing the level of assistance.